PROJECT SUMMARY. Magnetic resonance imaging (MRI) is one of the most useful tools available in the study of the brain and its processes. However, many brain imaging techniques are limited by the complexities of the MRI signal which make quantification of biological parameters difficult. A technique developed in our lab, called QUTE-CE MRI, has been shown to provide high resolution quantitative imaging of nanoparticle concentration. The long term goal of this research is to develop a functional brain imaging modality that may be useful for both basic neuroscience research and clinical applications. The objective of this specific project is to measure absolute quantitative changes to brain vasculature before and after oxycodone administration and addiction. This objective will be accomplished via execution of two specific aims; (1) Apply QUTE-CE MRI to functional imaging (fMRI) to create quantitative functional cerebral blood volume (CBV) scans. This will take the ability of the technique to quantify nanoparticle concentration and use it to quantify the amount of blood in each region of the brain based on a known blood concentration of the nanoparticles, improving on the work that I have been published for previously. (2) Apply the technique to the problem of drug addiction by evaluating chronic and acute regional changes in CBV to oxycodone administrations. The vasculature of the brain dynamically allocates blood in response to changes in activity, with this technique we may be able to absolutely quantify these dynamic changes with unprecedented accuracy. Vascular organization must address the common patterns of brain activity activity and we hypothesize that addicts who have chronically been exposed to a drug may have underlying compensatory changes to their vasculature. This project is innovative because the technique provides a new modality for brain imaging. It is significant because it may give new information about the process of addiction and response to oxycodone, the technique uses only standard MRI equipment combined with an FDA approved nanoparticle injection so it could easily be translated to clinical scans, and a wide variety of diseases are known to have vascular abnormalities which could be studied (and potentially diagnosed) via this technique.